• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권3호
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• pp.107-110
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• 2006

We fabricated the monolayers onto QCM by self-assembly using viologen, which has been widely used as electron acceptor. A gold electrode of the QCM was cleaned by piranha solution and prepared the ethanol-acetonitrile(1:1) solution with 2 m mol/l viololgen compounding of pure hi gas. We determined the time dependence to resonant frequency shift during self-assembly process and the electrochemical behavior of the self-assembled viologen monolayers by cyclic voltammetry. With increasing scan rate, the redox peak current of the viologen increased linearly. This was signified that the redox reaction was reversible. The EQCM measurements revealed the anions transfer during redox reactions, respectively. From the EQCM data, the well-defined shape peaks were nearly equal charges by cyclic voltammetry.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.2020-2021
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• 2007

Viologen derivative has been widely investigated because of their well-electrochemical behavior including the electron acceptor for the electric charge delivery mediation of the devices. The viologen exist in three main oxidation states, namely, $V^{2+}{\rightleftarrows}V^{{\cdot}+}{\rightleftarrows}V^0$. These redox reactions are highly reversible and can be cycled many times without significant side reaction. In this paper, we determined the time dependence to resonant frequency shift of QCM during self-assembly process and the electrochemical behavior of the self-assembled viologen monolayers by electrochemical QCM method. The redox reactions of viologen were highly reversible and the EQCM has been employed to monitor the electrochemically induced adsorption of SAMs during the redox reactions.

• Bulletin of the Korean Chemical Society
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• 제28권10호
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• pp.1792-1796
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• 2007

Insulating effects on Au electrode according to the thickness and density of coated materials are well-known. To do electrochemical immunoassay reproducibly the glod electrode would be coated with self-assembled monolayers and antobodies. To get reproducibility, the antobody monolayer should be packed at highest density so that the amount of immobilized antibody at defined area should be the same. The calix[4]crown-5 SAMs could provide the basis for the antibodies to be immobilized reproducibly and at highest density. But the insulating effect would be highest too. We proved that the compactly packed protein monolayers on SAMs inhibited the electron transfer by block the free shuttling of redox molecules. The inhibition was minimized by inserting redox molecules in between the proteins during immobilization process. In this paper, we demonstrated that the calix[4]crown-5 SAMs would provide the protein monolayers with highest density and new method to minimize the insulating effect by inserted redox molecules in between the compactly packed protein monolayers.

• 분석과학
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• 제11권5호
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• pp.332-340
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• 1998

Salicylaldehyde와 2-hydroxy-1-naphthaldehyde를 2-aminophenol과 2-amino-p-cresol에 반응시켜 세자리 Schiff base 리간드($SIPH_2$, $SIPCH_2$, $HNIPH_2$, $HNIPCH_2$)들을 합성하였다. 이들 리간드를 Ni(II) 이온과 반응시켜 세자리 Schiff base Ni(II) 착물들을 합성 하였다. 이들 리간드와 그 착물들의 가상적인 구조와 특성을 원소분석, $^1H$-NMR, IR, UV-vis 분광법과 열 무게 분석법으로 알아보았다. Schiff base 리간드와 Ni(II) 착물의 몰비는 1:1로 결합하며, Ni(II)착물들은 3분자의 수화물이 배위된 6배위의 8면체 구조임을 알았다. 지지 전해질로서 0.1 M TBAP를 포함한 DMSO 용액에서 순환 전압전류법과 미분 펄스 전압전류법으로 세자리 Schiff base 리간드와 이들의 Ni(II) 착물들의 전기 화학적인 산화 환원 과정을 알아보았다. 세자리 Schiff base 리간드들의 전기 화학적 환원은 확산 지배적이고 비가역적으로 진행되었다. Ni(II) 착물의 전기화학적 환원과정은 1단계 1전자 반응으로 확산 지배적이고 준가역적으로 진행되었다. Ni(II) 착물들의 환원전위는 [$Ni(II)(HNIP)(H_2O)_3$]>[$Ni(II)(SIP)(H_2O)_3$]>[$Ni(II)(SIPC)(H_2O)_3$]>[$Ni(II)(HNIPC)(H_2O)_3$]순으로 양전위 방향으로 이동하였으며, 리간드의 영향은 크게 받지 않았다. 이들 결과로 부터 본 연구에서 합성한 Ni(II)착물은 [$Ni(II)(HNIPC)(H_2O)_3$] 착물이 DMSO용매에서 가장 안정함을 알 수 있다.

• 공업화학
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• 제23권1호
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• pp.119-123
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• 2012

본 연구는 Mn/$TiO_2$ 촉매를 이용한 저온 $NH_3$-SCR 반응에서 산소의 역할에 대한 영향을 기술하였다. 촉매의 격자산소는 저온 SCR 반응에 참여하며, 기상의 산소는 환원된 촉매를 재산화 시키는 역할을 한다. 이러한 산소의 redox 특성은 SCR 반응활성에 중요한 요소로 작용하며, 격자산소의 이용능력은 표면에 노출된 망간의 산화상태에 큰 영향을 받는다. $TiO_2$ 담체 표면에 존재하는 Mn이 $MnO_2$의 망간산화물 형태로 존재할 때가 $Mn_2O_3$의 형태로 존재할 때보다 우수한 redox 특성을 가지며, 이러한 망간의 산화상태는 $TiO_2$의 비표면적에 큰 영향을 받는다.

• 폴리머
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• 제35권6호
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• pp.586-592
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• 2011

본 연구에서는 전바나듐 레독스-흐름 전지용 음이온교환막의 제조를 위하여 vinylbenzyl chloride-co-styreneco-hydroxyethyl acrylate(VBC-co-St-co-HEA) 공중합체를 합성하였으며, 아민화 및 가교 반응을 통하여 음이온교환막을 제조하였다. 구조확인을 위하여 FTIR, $^1H$ NMR, TGA, GPC 분석을 하였으며, 음이온교환막의 함수율, 이온교환용량, 전기저항, 이온전도도 및 전바나듐 레독스-흐름 전지의 효율을 측정하였다. 음이온교환막의 이온교환용량, 전기저항, 이온전도도는 각각 1.17 meq/g, $1.9{\Omega}{\cdot}cm^2$, 0.009 S/cm이었으며, 전바나듐 레독스-흐름 전지 효율 실험 결과 충 방전효율, 전압효율 및 에너지효율은 각각 99.5, 72.6, 72.1%이었다.

• Bulletin of the Korean Chemical Society
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• 제15권3호
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• pp.181-183
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• 1994

• 한국수소및신에너지학회논문집
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• 제22권4호
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• pp.443-450
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• 2011

The three-reactor chemical-looping process (TRCL) for the production of hydrogen from natural gas is attractive for both $CO_2$ capture and hydrogen production. In this study, redox property of $Fe_2O_3$ and $WO_3$ supported with $ZrO_2$ and $MgAl_2O_4$ were studied with temperature programmed oxidation/reduction (TPO/R) experiment. All metal oxides were prepared by ball mill method. Metal oxides supported with $ZrO_2$ showed the good redox property in TPO and TPR tests. Reduction behavior was matched well the theoretical reduction mechanism. Metal oxides supported with $MgAl_2O_4$ formed a solid solution ($MgFe_{0.6}Al_{1.4}O_4$, $MgWO_4$). $Fe_2O_3$ showed more narrow reaction range and lower reaction temperature than $WO_3$.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.260-266
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• 2012

Syngas and hydrogen from the $CeO_2/ZrO_2$ coated foam devices were investigated under simulated solar radiation. The $CeO_2/ZrO_2$ coated SiC, Ni and Cu foam device were prepared using drop-coating method. Syngas production step was performed at $900^{\circ}C$, and hydrogen production process was performed for ten repeated cycles to compare the CeO2 conversion in syngas production step, $H_2$ yield in hydrogen production step and cycle reproducibility. The produced syngas had the $H_2$/CO ratio of 2, which was suitable for methanol synthesis or Fischer-Tropsch synthesis process. In addition, syngas and hydrogen production process is one of the promising chemical pathway for storage and transportation of solar heat by converting solar energy to chemical energy. After ten cycles of redox reaction, the $CeO_2/ZrO_2$ was analyzed using XRD pattern and SEM image in order to characterize the physical and chemical change of metal oxide at the high temperature.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.23-27
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• 2003

Molecular self-assembled of surfactant viologen are of recent interest because they can from functional electrodes as well as micellar assemblies, which can be profitably utilized for display devices, photoelectrochemical studies and electrocatalysis as electron acceptor or electron mediator. Fromherz et al studied the self-assembly of thiol and disulfide derivatives of viologens bearing long n-alkyl chains on Au electrode surface. The electrochemical behavior of self-assembled viologen monolayer has been investigated with QCM, which has been known as nano-gram order mass detector. The self-assembly process of viologen was monitored using resonant frequency$({\Delta}F)$ and resonant resistance(R). The redox process of viologen was observed with resonant frequency $({\Delta}F)$.